DOS ain't dead - p7zip 4.65 for FreeDOS (performance)

p7zip 4.65 for FreeDOS (performance) (Announce)

posted by Rugxulo , Usono, 26.05.2009, 21:46

> > > I can only guess because of WATT-32 + GNU pth slowing it down
> (although
> > > admittedly MSVC might be better than GCC these days, too).
> >
> > And DGJPP C file I/O library costs 10% ...
>
> I don't think it's that bad. Usually it's pretty good performance.
> (Although WATT-32 is much slower than libsocket, but I don't think the
> latter works anymore ... at least not for my weak efforts.) But it depends
> on what the C library was compiled for. You could probably get better
> performance recompiling the C lib from CVS with latest GCC via
> -mtune=i686 (2.04 used GCC 3.3.2, I think, while 2.03p2 used 2.8.1,
> both almost definitely using the default -mtune=pentium, heh).

The real problem is relying on sockets (which are only needed for GNU pth using the high-level pthreads API). It's too complex, and I'm too unfamiliar to strip it out myself. This was one advantage to Kostylev's builds, he used FSU Pthreads, which didn't need sockets. However, I'm lucky I was able to build it at all (and my patch should make it 100% possible for anyone to do so).

In particular, IIRC, I compiled 4.65 with -Os (G++ 4.3.2) because it's such a huge bloated program (and -O2 wasn't much faster, if at all, in my testing). 7za got "-mtune=i686" and (for comparison / equality) 7zr got "-mtune=i586". You might (??) get better with latest G++ 4.4.0, but don't count on it.

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Complete thread:

p7zip 4.65 for FreeDOS - Rugxulo, 16.04.2009, 17:48 (Announce)
- p7zip 4.65 for FreeDOS - rr, 16.04.2009, 21:54
  - p7zip 4.65 for FreeDOS - Rugxulo, 16.04.2009, 22:10
- p7zip 4.65 for FreeDOS | Ibiblio has 4.61 only - DOS386, 22.05.2009, 08:12
  - p7zip 4.65 for FreeDOS | Ibiblio has 4.61 only - Rugxulo, 23.05.2009, 02:26
    - p7zip 4.65 for FreeDOS | Ibiblio has 4.61 only - DOS386, 23.05.2009, 02:40
      - p7zip 4.65 for FreeDOS | Ibiblio has 4.61 only - Rugxulo, 23.05.2009, 02:42
        p7zip 4.65 for FreeDOS (performance) - Rugxulo, 26.05.2009, 21:46
      - p7zip 4.65 for FreeDOS | GCC 4.4.0 -O2 -mtune=i686 - Rugxulo, 29.05.2009, 02:41
        p7zip 4.65 for FreeDOS | GCC 4.4.0 -O2 -mtune=i686 - DOS386, 05.06.2009, 07:20
        p7zip 4.65 for FreeDOS | GCC 4.4.0 -O2 -mtune=i686 - Rugxulo, 05.06.2009, 07:47
        p7zip 4.65 for FreeDOS | GCC 4.4.0 -O2 -mtune=i686 - DOS386, 05.06.2009, 08:35
        p7zip 4.65 for FreeDOS | GCC 4.4.0 -O2 -mtune=i686 - Rugxulo, 11.06.2009, 04:13